1. Field of the Invention
The present invention relates generally to an eductor cleaner and, more specifically, to a water-powered eductor cleaner utilizing a pendulum cleaning device.
2. Description of Related Art
Eductors are used to convey material from one location to another. For example, as pressurized water is directed through a nozzle into a chamber or venturi of the eductor, a low pressure area is formed in the venturi. The low pressure area will “pull” air, water, ash, and any other free floating materials from the venturi towards the throat of the eductor. In other words, the low pressure area creates a vacuum that sucks materials from within the venturi to a subsequent location. For example, coal fired plants use eductors to move coal fly ash from small collection hoppers to larger storage areas.
As material is inserted into the eductor through a material intake, the material may come in contact with the pressurized water supplied via the nozzle. Many types of materials, such as coal fly ash (calcium carbonate), can become sticky when mixed with water. Unfortunately, the sticky material can begin to accumulate on the walls of the eductor. Further, the accumulating material can then subsequently clog the nozzle of the eductor, thereby interfering with the efficient use of the eductor. As the material continues to accumulate on the walls of the throat of the eductor, the low pressure area formed weakens, and can no longer pull materials out of the eductor.
To clean out the accumulated material on the walls and throat of the eductor, the eductor must be taken out of service so that the venturi can be scraped with a rod or hard brush. The process of cleaning out the venturi by scraping the accumulated materials off the walls and throat of the eductor can be hazardous, as such process requires an individual to enter a space-limiting and fall hazard environment.
To address the accumulation of dust and materials in other industries, rapping mechanisms have been used to remove the accumulation of materials from various devices. For example, electrostatic precipitators are often used to collect dust by utilizing an electrical charge (e.g., static electricity). The electrical charge attracts the dust particles that then accumulate near the location of the electrical charge. Subsequently, a rapping mechanism can be used to dislodge or knock-off the accumulated dust, which can then be disposed of properly.
U.S. Pat. No. 1,444,997 to Anderson discloses the use of chains or wires to decrease the amount of precipitated matter adhered thereto, so as to facilitate the removal of the precipitated matter from electrodes. Further, Anderson provides the process of shaking or raising and lowering an electrode to dislodge particulate matter that has attached to it. To collect the precipitated matter, the chains or wires are electrified to a high voltage to produce a corona, which charges the particles within gas moving by the chains or wires. The charged particles are then attracted to an electrically charged plate (e.g., electrode) having an opposite electric charge and being positioned near the chains or wires. The chains and wire, however, are not used as rapping mechanisms to dislodge the collected particles on the electrode. Instead, the electrode is shaken or raised and lowered to remove the accumulated matter. Further, when the chains or wire become dirty, they are cleaned by a separately powered device similar to a rapper.
Another electrostatic precipitator is disclosed in U.S. Pat. No. 1,479,271 to Wolcott. The electrostatic precipitator uses a jarring means to jar or agitate a screen, chain, or wire so that the high tension electrodes may also be vibrated, thereby dislodging material that has accumulated on the electrodes. The screen, chain, or wire is used to charge particulate matter by using a high voltage. The charged particulate matter is then attracted to an oppositely charged electrode.
U.S. Pat. Nos. 3,951,624 and 4,026,683 to Snader and Snader et al., respectively, disclose the use of a baffle that prevents particles from becoming lodged between a hopper and the baffle upon discharge of the particles from the hopper. Link chains of various lengths are used to meet the shape of a flexible portion to the sides of the hopper. Being flexible, the chains will move to permit accumulations of dust particles ahead of the chains to slide downward into a precipitator. Snader et al. further discloses a rapper assembly used to vibrate a rigid portion and a flexible portion to dislodge the dust particles thereon, causing the material to fall into the precipitator.
U.S. Pat. No. 3,966,436 to Archer discloses the clashing of certain elements of a discharge electrode in order to effectively remove accumulated particles that are attached thereon. Archer provides an improved discharge electrode that captures dust particles using an electrostatic charge, but can be cleaned by clashing certain parts of the electrode to remove the accumulated material.
Further, U.S. Pat. Nos. 4,968,330 and 5,009,667, both to Wolf et al., disclose subparts for an electrostatic precipitator having a chain screen made up of individual chains of varying lengths. Below the chain support is a cam that functions as a rapper by lifting the chain support and then allowing it to fall at periodic, predetermined times. Additionally, dust which collects on collecting electrodes is dislodged by rappers that jolt the electrodes. By lifting and dropping the chain support, the chain rapper permits the various chains to hit against each other, thereby permitting the dust that has accumulated on a distributor to pass through the chain screen into a hopper. The chains are designed to separate particles of varying sizes, but are not designed to actually clean the electrodes of the precipitator.
Yet another precipitator is disclosed in U.S. Pat. No. 5,334,238 to Goodson et al. A variation for dislodging particles is provided, wherein a plurality of flexible tubes are used for passing a stream of gas onto precipitator plates. As the stream of gas flows through the flexible tubes, it causes a natural reaction propelling the unrestrained tubes in random directions (often colliding with the wall or other internal structures) such that the exiting gas is directed primarily at the precipitator plates. As the exiting gas encounters the precipitator plates, the fine particles adhered to the plates are removed and carried away. An external blower is used to power the hosed during the cleaning process, which generally occurs after accumulation of materials has occurred.
Also, U.S. Pat. No. 6,360,680 to Breen et al. is directed toward a base furnace having plates used to accumulate particle matter. As disclosed, the plates are rapped at regular intervals; thereby releasing the fly ash attached to the plates, which then falls and collects in a reservoir.
While useful for their intended purposes, none of these devices can be used to adequately clean an eductor as described above. More specifically, an electrostatic precipitator would not be effective in an eductor using high-pressured water streams to create a low-pressure area for removing particulate matter from the chamber of the eductor, as the water flow would interfere with the electrically charged electrodes or plates. Further, most of the devices described above require a separate energy source for removing the accumulated material (e.g., for activating the rapper).
What is needed, therefore, is a self-cleaning water-powered eductor that prevents the accumulation of material within the venturi of the eductor. Moreover, what is needed is a water-powered eductor having a pendulum cleaning device that uses the energy from the water source to activate the pendulum motion, thus cleaning the inside of the eductor. A beneficial self-cleaning water-powered eductor should not use a separate energy source for removing accumulated materials within the eductor. Instead, the self-cleaning water-powered eductor should use the kinetic energy provided by the high-pressured water streams to initiate the pendulum cleaning device. It is to such a device that the present invention is primarily directed.